The present invention relates to molds in metal casting systems wherein an electromagnetic inductor serves to shape molten metal prior to the solidification thereof, and more particularly, to an adjustable mold wherein the side walls of the mold are movable so as to cast ingots of various different sizes.
Electromagnetic casting systems to which the instant invention relates includes systems for electromagnetically casting wherein molten metal is introduced at a controlled rate onto a movable bottom block located within a loop-shaped electrical inductor. The bottom block is lowered at a controlled rate with metal flow being controlled in accordance with this rate to form an ingot. The molten metal so introduced is confined laterally inside the inductor by an electromagnetic field generated by an alternating current in the inductor. The molten metal is thus formed into a shape in a horizontal plane similar to the inductor. The emerging bottom block and ingot are subjected to rapid cooling by the application of a coolant, such as water, to solidify the ingot into this shape.
In most of these type systems there is a tapered electromagnetic shield or screen located inside the inductor arranged coaxially therewith made of a non-magnetic, but electrically conductive, metal, such as stainless steel. The shield, because of its taper, serves to attenuate the magnetic field of the inductor upwardly, thereby lessening the electromagnetic forces restraining the ingot at the top as opposed to those at the lower edge of the shield. The advantages of such a shield are more fully described in U.S. Pat. No. 3,605,865 to Getselev.
As is the case in the conventional casting of rectangular ingots by the direct chill method, ingots cast by the above-noted electromagnetic casting systems typically have somewhat concave side walls. The reasons for this less than ideal configuration are discussed in detail in U.S. Pat. No. 4,216,817 to Meier which is incorporated herein by reference.
Molds for use in the electromagnetic casting systems noted above are quite costly. One of the chief reasons for the high cost of the molds is due to the critical tolerances which must be maintained when machining a mold. In addition, due to the fact that numerous ingots of various sizes are normally cast, one is required to maintain an inventory of molds of various sizes which is economically undesirable. Naturally, it would be highly desirable to provide a mold for electromagnetic casting systems wherein the side walls are readily adjustable so as to enable the casting of various sizes of ingots.
Accordingly, it is the principal object of the present invention to provide an adjustable mold for use in electromagnetic casting.
It is a particular object of the present invention to provide an adjustable mold for electromagnetic casting which allows for ingots with substantially flat side walls to be cast.
It is a further object of the present invention to provide an adjustable mold for electromagnetic casting wherein the side walls are readily adjustable.
It is a still further object of the present invention to provide an adjustable mold for electromagnetic casting which is simple in construction and economic to manufacture.
Further objects and advantages of the present invention will appear hereinbelow.